package com.ankurm.hibernatedemo.scenario;

import com.ankurm.hibernatedemo.model.WidgetIdentity;
import jakarta.persistence.EntityManager;
import jakarta.persistence.EntityManagerFactory;
import org.hibernate.SessionFactory;
import org.hibernate.stat.Statistics;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.CommandLineRunner;
import org.springframework.context.annotation.Profile;
import org.springframework.stereotype.Component;

/**
 * Backs ankurm.com post 4861 ("inserting objects efficiently") and
 * docs/03-inserting-objects.md. Captured verbatim into docs/output/insert-identity.txt by
 * {@code scripts/run.sh insert-identity}.
 *
 * <p>Same {@code hibernate.jdbc.batch_size} and {@code hibernate.order_inserts} settings as
 * {@link InsertSequenceRunner} -- the only difference is {@link WidgetIdentity}'s
 * {@code GenerationType.IDENTITY} strategy. Compare the two captured output files directly;
 * the diff between them is the entire point of this pair.
 */
@Component
@Profile("insert-identity")
public class InsertIdentityRunner implements CommandLineRunner {

    private static final Logger DEMO = LoggerFactory.getLogger("DEMO");
    private static final int ROW_COUNT = 30;

    private final EntityManagerFactory emf;

    public InsertIdentityRunner(EntityManagerFactory emf) {
        this.emf = emf;
    }

    @Override
    public void run(String... args) {
        SessionFactory sessionFactory = emf.unwrap(SessionFactory.class);
        Statistics stats = sessionFactory.getStatistics();
        stats.clear();

        DEMO.info("--- inserting {} WidgetIdentity rows (GenerationType.IDENTITY) ---", ROW_COUNT);
        EntityManager em = emf.createEntityManager();
        em.getTransaction().begin();
        for (int i = 1; i <= ROW_COUNT; i++) {
            em.persist(new WidgetIdentity("identity-" + i));
        }
        em.getTransaction().commit();
        em.close();

        DEMO.info("entityInsertCount     = {}", stats.getEntityInsertCount());
        DEMO.info("prepareStatementCount = {}", stats.getPrepareStatementCount());
        DEMO.info("(with IDENTITY, expect prepareStatementCount to land close to entityInsertCount --" +
                " each insert has to go to the database immediately to hand back the generated key,"
                + " so there is nothing left for hibernate.jdbc.batch_size to batch)");
    }
}